Get the lead out: Clean air tied to decline in violent crime

Leaded gasoline: The gift that kept on givingDon’t believe the evening news: Violent crime and murder have been declining steadily for two decades in this country. Last year was statistically the safest year in almost four decades for Americans who weren’t Corey Haim, Ronnie James Dio, or Captain Beefheart, and everyone’s got a theory as to why.

Some claim the decline of crack cocaine is the answer, or credit the rise of cell phones, while others point to improved policing techniques and the use of statistical crime modeling. I personally like the theory that the “three strikes and you’re out” policies brought us round the bend: Tying our legal system to the obtuse and arbitrary rules of arcane bat-and-ball games clearly smacks of crime-fighting genius. (Fun Factoid: Many of our cricket-loving British friends thank their once controversial “leg before wicket” law for completely eliminating regicide in the 20th century.)

A recent article in Slate posits that the continued decline may be the result of the “Obama Effect“: With an African American in the White House, blacks are optimistic about the future, and as consumer satisfaction goes up, crime goes down. But there’s another factor that may underlie all the others: It may turn out that violence has even more in common with a 1971 El Camino than we’d ever suspected. Yes, both are embarrassing hallmarks of American culture, but they also both sputter without leaded gasoline.

Lead was first added to gasoline in the 1920s, and it made cars go like stink, but in 1973, the EPA called gasoline “the most ubiquitous source of lead found in the air, dust, and dirt in urban areas.” As a result, the average American’s blood had enough lead to run a Chinese toy factory.

It turns out that low-level lead poisoning, especially in the first three years of life, has significant and often measured consequences. Children with high levels of lead in their blood have lower IQs and are more prone to attention deficit hyperactivity disorder, impulsivity, and aggression. Further, the Public Library of Science-funded Cincinnati Lead Study observed 250 kids over a 20-year period and showed that children with increased levels of lead had decreased brain mass as adults, with heightened effects on the parts of the brain that regulate self-control. The results were even more pronounced for boys.

As lead poisoning rose, so did violent crime. Lead levels in gasoline grew through the ’40s and ’50s. As the children who huffed those fumes matured, crime rates began to climb dramatically, growing 350 percent from the mid ’60s until its 1991 crescendo.

A University of Pittsburgh study showed that children with increased blood-lead levels (but still within the range of EPA-approved levels) showed greatly increased tendencies toward aggression and were four times as likely to get into trouble with the law. The study estimated between 18 and 38 percent of delinquency in the Pittsburgh area could be pinned to lead poisoning.

The good news is that the Clean Air Act changed the game. From 1975 to 1990, lead in gasoline dropped a precipitous 99 percent. Correspondingly, lead in Americans’ blood dropped over 81 percent from 1976 to 1991.

Now, according to research by Amherst economist Jessica Wolpaw Reyes, the lead is disappearing and the violent crime rate is dropping as well, with a 56 percent decrease in violent crime from 1992 to 2002. Even with an economy plummeting to record lows and Dancing With the Stars ratings rocketing to horrifying highs — factors traditionally associated with driving people toward desperate mayhem — violent crime rates continue to drop to levels not seen since the early ’60s.

To put it into context, had the murder rate remained steady at its 1991 rate, 170,000 more Americans would now be dead — a number greater than the population of Dover, Del. By 2020, all adults in their 20s and 30s will have grown up with no exposure to leaded gasoline, and if the theory holds, violent crime will continue its decline.

The Clean Air Act and the EPA helped reverse the trend of violent crime and, while there aren’t as many El Caminos on the road, the auto industry has soldiered on even without its precious lead, turning its attention to fuel–efficientalternatives to the poison belchers of the 1970s.

Yet despite the success of the Clean Air Act, both intentional and unintentional, legislators continue to push off environmental regulations claiming economic concerns. Just last month, the Obama administration cited a disappointing jobs report as reason to withdraw the EPA’s Ozone National Ambient Air Quality Standards. This, despite the EPA projecting that the new standards would save 4,300 lives and prevent 7,000 hospital visits each year.

And those are just the expected benefits. In 1975, no one predicted cutting lead from gas would cause a drop in violent crime. Who knows what cutting ozone pollution might do? Perhaps scientists in 30 years will realize that ozone poisoning made us laugh at More Cowbell or caused Bruce Willis to think Uggs would be a good look.